New treatment of native methods.

tests/compiler/dart2js/unparser_test.dart

 // Copyright (c) 2012, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 #import('parser_helper.dart');
 #import("../../../lib/compiler/implementation/tree/tree.dart");
 
 testUnparse(String statement) {
   Node node = parseStatement(statement);
   Expect.equals(statement, node.unparse());
@@ skipping 21 matching lines @@
 }
 
 testClosure() {
   testUnparse('var x=(var x)=> x;');
 }
 
 testIndexedOperatorDecl() {
   testUnparseMember('operator[](int i)=> null;');
 }
 
+testNativeMethods() {
+  testUnparseMember('foo()native;');
+  testUnparseMember('foo()native "bar";');
+  testUnparseMember('foo()native "this.x = 41";');
+}
+
 main() {
   testGenericTypes();
   testForLoop();
   testEmptyList();
   testClosure();
   testIndexedOperatorDecl();
+  testNativeMethods();
 }